UPDATE 12:30 AM: Police have updated the casualty numbers, saying that along with the two women who were confirmed dead at the scene, two of the 22 injured are in critical condition. Two businesses were also located on the ground floor of the two buildings, a piano-repair company and a Spanish Christian church. The church’s pastor, who also owns one of the buildings, is on the scene working with police to figure out if anyone is missing.

UPDATE 11:50 AM: Con Edison, a gas and power company, has confirmed that they received a call about a strong smell of gas. They dispatched a crew, but the explosion had already happened before they arrived. However, they have not confirmed if the explosion was caused by the leak in question. As soon as the fires are contained, authorities will be able to gather more details about the cause.

A New York City apartment building has exploded in huge flames and billowing black smoke, leading to the collapse of two adjacent buildings. Two women were killed in the blast, which also injured at least 18 people and left many more missing.

Residents heard a large explosion near Park Avenue and 116th Street in East Harlem around 9 a.m. Wednesday. The five-story buildings have been reduced to rubble, possible trapping numerous people inside.

Eoin Hayes, 26, said the explosion shook his entire apartment building in Harlem at about 9:30 a.m. He ran to the window and saw flames consuming one building and smoke rising into the air.

"I was in my bedroom and the explosion went off, it kind of shook the whole building," Hayes said. "You could feel the vibrations going through the building."

Hayes lives less than 10 blocks from where the explosion happened. He said the fire consumed one building and then moved on to another building adjacent to it, though about 40 minutes later the flames had subsided and there was mostly just smoke. Both buildings appeared to be residential.

"I ran to the window and saw the fire and the smoke going up and the sirens start," Hayes said.

Sidewalks for blocks around are littered with broken glass from shattered storefront and apartment windows. Witnesses say the blast was so powerful it knocked groceries off the shelves of nearby stores.

Authorities have not revealed the cause of the explosion, but it seems likely to have been a gas leak, as many witnesses at the scene said the smell of gas was prevalent beforehand. A press conference has been scheduled for early afternoon.

The site is next to Metro-North commuter railroad tracks. Train service is halted to and from Grand Central Terminal.

The fire department said it sent nearly 170 members to the scene.

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